Structural shapes that can be made with this metal forming process include I-beams, H-beams, T-beams, U-beams, angle iron, channels, bar stock, and railroad rails.
The most commonly rolled material is structural steel.
it is made by Hot rolling.

Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed through a die of the desired cross-section. Rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform.

A two high rolling mill consists of two rolls which rotate At the same speed but in opposite direction.

A three high rolling mill consists of three rolls placed one above the other and the upper and bottom rolls rotate in the same direction whereas the middle roll rotates in opposite direction.